Hi I am trying to combine a set of different grids into one. I know there is the option with the rhino plugin but I cant seem to find on Grasshopper. many thanks!
@rajaa What if you want to merge grid with a different number of points. something like the following picture. 
Yup, this becomes a bit more tricky since you have to manage the tree. Sometimes it is easier to split the tree, merge in the order you need to insert the new part. If you post an .gh example, I can try to help